/*
 * Copyright (C) 2008 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package zhoufu.sz.sanxiao_check.weiget.zxing.view;

import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.View;
import com.google.zxing.ResultPoint;
import java.util.Collection;
import java.util.HashSet;
import zhoufu.sz.sanxiao_check.R;
import zhoufu.sz.sanxiao_check.weiget.zxing.camera.CameraManager;

/**
 * This view is overlaid on top of the camera preview. It adds the viewfinder
 * rectangle and partial transparency outside it, as well as the laser scanner
 * animation and result points.
 *
 * @author dswitkin@google.com (Daniel Switkin)
 */
public final class ViewfinderView extends View
{

    private static final int[] SCANNER_ALPHA = {0, 64, 128, 192, 255, 192,
            128, 64};
    private static final long ANIMATION_DELAY = 100L;
    private static final int OPAQUE = 0xFF;

    private final Paint                   paint;
    private       Bitmap                  resultBitmap;
    private final int                     maskColor;
    private final int                     resultColor;
    private final int                     frameColor;
    private final int                     laserColor;
    private final int                     resultPointColor;
    private       int                     scannerAlpha;
    private       Collection<ResultPoint> possibleResultPoints;
    private       Collection<ResultPoint> lastPossibleResultPoints;

    // 需要转换为dp
    // 垂直角落的宽高
    private int CornerVWidth = 5;
    private int CornerVHeight = 25;
    // 水平角落的宽高
    private int CornerHWidth = 25;
    private int CornerHHeight = 5;

    // 中间线Y轴移动的变量
    private int lineOffset = CornerHHeight;
    private int lineSpeed = 10;

    float density;// 屏幕密度

    // This constructor is used when the class is built from an XML resource.
    public ViewfinderView(Context context, AttributeSet attrs) {
        super(context, attrs);
        // Initialize these once for performance rather than calling them every
        // time in onDraw().
        paint = new Paint();
        Resources resources = getResources();
        maskColor = resources.getColor(R.color.viewfinder_mask);
        resultColor = resources.getColor(R.color.result_view);
        frameColor = resources.getColor(R.color.viewfinder_frame);
        laserColor = resources.getColor(R.color.viewfinder_laser);
        resultPointColor = resources.getColor(R.color.possible_result_points);
        scannerAlpha = 0;
        possibleResultPoints = new HashSet<ResultPoint>(5);

        // 将像素转换为dp
        density = getContext().getResources().getDisplayMetrics().density;
        CornerVWidth *= density;
        CornerVHeight *= density;
        CornerHWidth *= density;
        CornerHHeight *= density;
    }

    @Override
    public void onDraw(Canvas canvas) {
        Rect frame = CameraManager.get().getFramingRect();
        if (frame == null) {
            return;
        }
        int width = canvas.getWidth();
        int height = canvas.getHeight();

        // Draw the exterior (i.e. outside the framing rect) darkened
        paint.setColor(resultBitmap != null ? resultColor : maskColor);
        canvas.drawRect(0, 0, width, frame.top, paint);
        canvas.drawRect(0, frame.top, frame.left, frame.bottom + 1, paint);
        canvas.drawRect(frame.right + 1, frame.top, width, frame.bottom + 1,
                paint);
        canvas.drawRect(0, frame.bottom + 1, width, height, paint);

        if (resultBitmap != null) {
            // Draw the opaque result bitmap over the scanning rectangle
            paint.setAlpha(OPAQUE);
            canvas.drawBitmap(resultBitmap, frame.left, frame.top, paint);
        } else {
            // Draw a two pixel solid black border inside the framing rect
            // paint.setColor(frameColor);
            // canvas.drawRect(frame.left, frame.top, frame.right + 1,
            // frame.top + 2, paint);
            // canvas.drawRect(frame.left, frame.top + 2, frame.left + 2,
            // frame.bottom - 1, paint);
            // canvas.drawRect(frame.right - 1, frame.top, frame.right + 1,
            // frame.bottom - 1, paint);
            // canvas.drawRect(frame.left, frame.bottom - 1, frame.right + 1,
            // frame.bottom + 1, paint);
            // 画角
            paint.setColor(Color.GREEN);
            // 左上
            canvas.drawRect(frame.left, frame.top, frame.left + CornerVWidth,
                    frame.top + CornerVHeight, paint);
            canvas.drawRect(frame.left, frame.top, frame.left + CornerHWidth,
                    frame.top + CornerHHeight, paint);
            // 右上
            canvas.drawRect(frame.right - CornerVWidth, frame.top, frame.right,
                    frame.top + CornerVHeight, paint);
            canvas.drawRect(frame.right - CornerHWidth, frame.top, frame.right,
                    frame.top + CornerHHeight, paint);
            // 左下
            canvas.drawRect(frame.left, frame.bottom - CornerVHeight,
                    frame.left + CornerVWidth, frame.bottom, paint);
            canvas.drawRect(frame.left, frame.bottom - CornerHHeight,
                    frame.left + CornerHWidth, frame.bottom, paint);
            // 右下
            canvas.drawRect(frame.right - CornerVWidth, frame.bottom
                    - CornerVHeight, frame.right, frame.bottom, paint);
            canvas.drawRect(frame.right - CornerHWidth, frame.bottom
                    - CornerHHeight, frame.right, frame.bottom, paint);

            // Draw a red "laser scanner" line through the middle to show
            // decoding is active
            // 画中间线
            paint.setColor(laserColor);
            paint.setAlpha(SCANNER_ALPHA[scannerAlpha]);
            scannerAlpha = (scannerAlpha + 1) % SCANNER_ALPHA.length;
            // int middle = frame.height() / 2 + frame.top;
            int middle = frame.top + lineOffset;
            lineOffset += lineSpeed * density;
            if (lineOffset >= frame.bottom - frame.top - CornerHHeight) {
                lineOffset = CornerHHeight;
            }
            canvas.drawRect(frame.left + CornerVWidth, middle - 1, frame.right
                    - CornerVWidth, middle + 2, paint);
            // 画文本
            paint.setColor(Color.LTGRAY);
            paint.setTextSize(17 * density);
            String text = getResources().getString(R.string.screenRemind);
            // 左乘右除，2的几次方
            canvas.drawText(text, (width - getTextWidth(text, paint)) >> 1,
                    frame.bottom + 35 * density, paint);
            Collection<ResultPoint> currentPossible = possibleResultPoints;
            Collection<ResultPoint> currentLast     = lastPossibleResultPoints;
            if (currentPossible.isEmpty()) {
                lastPossibleResultPoints = null;
            } else {
                possibleResultPoints = new HashSet<ResultPoint>(5);
                lastPossibleResultPoints = currentPossible;
                paint.setAlpha(OPAQUE);
                paint.setColor(resultPointColor);
                for (ResultPoint point : currentPossible) {
                    canvas.drawCircle(frame.left + point.getX(), frame.top
                            + point.getY(), 6.0f, paint);
                }
            }
            if (currentLast != null) {
                paint.setAlpha(OPAQUE / 2);
                paint.setColor(resultPointColor);
                for (ResultPoint point : currentLast) {
                    canvas.drawCircle(frame.left + point.getX(), frame.top
                            + point.getY(), 3.0f, paint);
                }
            }

            // Request another update at the animation interval, but only
            // repaint the laser line,
            // not the entire viewfinder mask.
            postInvalidateDelayed(ANIMATION_DELAY, frame.left, frame.top,
                    frame.right, frame.bottom);
        }
    }

    /**
     * 获取文本宽度
     *
     * @param text
     * @param paint
     * @return
     */
    public int getTextWidth(String text, Paint paint) {
        Rect rect = new Rect();
        paint.getTextBounds(text, 0, text.length(), rect);
        return rect.width();
    }

    public void drawViewfinder() {
        resultBitmap = null;
        invalidate();
    }

    /**
     * Draw a bitmap with the result points highlighted instead of the live
     * scanning display.
     *
     * @param barcode An image of the decoded barcode.
     */
    public void drawResultBitmap(Bitmap barcode) {
        resultBitmap = barcode;
        invalidate();
    }

    public void addPossibleResultPoint(ResultPoint point) {
        possibleResultPoints.add(point);
    }

}
